Expanding pulley



(No Model.) 2 Sheets-Sheet 1.

. W. G. PINLAY.

EXPANDING'PULLBY.

No. 414,508. Patented Nov. 5, 1889.

UNITED STATES PATENT EEICE,

VILIAM G. FINLAY, OF LAXVRENCE, MASSACHUSETTS.

EXPANDING PU LLEY.

SPECIFICATION forming part 'of Letters Patent N o, 414,508, datedNovember 5, 1889.

Application filed February 23, 1889. Serial No. 300,897. (No model.)

To a-ZZ, whom it may concern:

Beit known that I, WILLIAM G. FINLAY, of Lawrence, in the county ofEssex and State of Massachusetts, have invented certain new and usefulImprovements in Expandinglulleys, ot' which the following is aspecification.

This invent-ion has for its object to provide an expanding pulley ofsimple construction adapted to be readily expanded and contracted and tobe retained at any desired adj ustment by the means used to effect theadj ustment. y

To these ends the invention consists in the improvements which I will.now proceed to describe and claim.

Of the accompanying drawings, forming a part of this speciication,Figure l represents a side view of a pulleyT provided withmyimprovenients, the pulley-supporting plates or sections beingexpanded. Fig. 2 represents a section on line fc a'. of Fig. l. Fig. 3repre sents a section on line y y of Fig. l. Fig. a represents a sideview of a portion of a papercutting machine having my improvement.

The same letters of reference indicate the same parts in all thefigures.

In the drawings, a represents the hub of the pulley, on which are formeda series of radial arms or spokes h l) I), provided with longitudinalslots or guides h', which also radiate from the hub.

c c c represent the belt-supporting plates or sections, each of which ispreferably curved longitudinally, as shown. Said plates are attached toor formed on slides d d d, which are iitted to move in the slots orguides b', and are provided with rack-teeth e on their rear sides.

f represents a circular plate, which is mounted to rotate independentlyon the hub c, and is provided on one side with a volute tooth or rib j,which extends from the periphery of the said plate to or nearly to thehub, and is engaged with the teeth con the plate-slides d, said teethbeing formed to fit the curvature of the volute tooth or rib f. Forconvenience I vwill call the plate f, with its volute tooth or rib, ascrolL It will be seen that the engagement of the scroll with the slidesd enables said scroll to y `move the slides d simultaneously toward orfrom the hub o. when said scroll is rotated and to hold the slides atany position to which they may be thus moved. The beltsupporting platesc may be therefore adj usted to an d held at any desired distance fromthe hub a, so that the diameter oi' the pulleyperiphery, which saidplates collectively form, may be increased by rotating the scroll in onedirection and decreased by rotating it in the opposite direction. Thefrictional contact of the slide-teeth e with the volute tooth f isusually sufiicient to prevent rattling or accident-al rotation of thescroll or plate f; but to increase said friction, and thereby preventthe possibility of rattling, I interpose springs h between the hub a andthe inner ends of the slides d, said springs exerting outward pressureon the slides d.. The hub a and slides d are provided with socketsreceiving` the ends of the springs 71.. The scroll f may be rotated toeit'ectthe described adjustment of the belt-supporting sections by handor by any suitable mechanism. I have here shown the periphery of saidscroll provided with gear-teeth t, formed to engage a worm on a shaftfo, Fig. l. Said shaft is journaled in a pivoted box p, and is providedwith two worms 'to to', one engaged with the upper portion of the scrollof au expanding pulley on a shaft .S and the other with the scroll of aduplicate pulley onanother shaft S so that the rotation of said shaft owill rotate the two pulleys in opposite direct-ions, and thereforeexpand one and contract the other. The pivoted box enables the shaft oto be moved to throw the two Worms w w simultaneously into and out ofengagement with the two pulleys.

The arrangement of parts last described is applicable to thepapercutting machine shown in Letters Patent No. 326,859, granted to meSeptember 22, 1885, the simultaneous expansion of one pulley and thecontraction ot the other pulley being for the purpose of regulating thelength of the sheets into which a web of paper is cut by said machine.

The improved expanding pulley forming the subject of this application isintended as a substitute, in a paper-cutting machine, for

the pulleys constructed as shown in said patent; but it is obvious thatsaid improved pulley maybe used for any other purpose to which it isapplicable.

I claim- 1. In an expanding pulley, the combination of a hub havingradial arms, toothed slides fitted to move radially on said arms andprovided with belt-supports, an independently-rotatable plate journaledon said hub and provided With a spiral or volute rib or tooth engagedwith said slides, and springs arranged to press the teeth of the slidesagainst the said tooth or rib, as set forth.

2. In an expanding pulley, the combination of a hub having radial arms,toothed

